Method of manufacturing pure niobium plate end-group components for superconducting high frequency accelerator cavity

Abstract

Targeting mass production, the present invention provides an advanced method of manufacturing pure niobium plate end-group components from pure niobium plate material for superconducting high frequency accelerator cavity by means of innovative shear-blanking followed by innovative forging procedures, wherein the invention is to convert the procedure/production method from the conventional machining or waterjet cutting followed by the conventional cold forging to the whole press-forming The invention gives the drastic effects on cost-effectiveness and press-performance.

The invention claimed is: 
     
       1. A method of manufacturing pure niobium plate end-group components for superconducting high frequency accelerator cavity used for an acceleration of charged particles, composing of
 (1) shear-blanking procedure of a pure niobium plate different from a conventional fine blanking, wherein a clearance that is defined as a gap between outer and inner diameters of respective shear-blanking punch and die is set to be very small value below 0.5% of pure niobium plate thickness to form a near net shape semi-product free from foreign objects on and below a material surface under restriction of the material on binding tool to generate counter force, and 
 (2) forging procedure at different temperatures from any of conventional hot or warm or cold forging, wherein press forging is conducted to be free from occurrence of blue brittleness/necking and to bring about prominent metal-flow, sufficient formability, size accuracy in any portion of a product and a margin of further press-forming by controlling forging temperature to be below 200° C. and beyond ambient room temperature, 
 wherein a manufacturing method of full machining or waterjet cutting followed by cold forging of said pure niobium plate end-group components is converted to a whole press-forming method. 
 
     
     
       2. Aforementioned method of shear-blanking pure niobium plate end-group components according to  claim 1 , wherein successive shear-blanking at higher speed than 100 mm/sec is carried out on said pure niobium plate and that shear-blanking tooling die is installed with a cooling device for extraction of heat generated in said procedure. 
     
     
       3. A method of manufacturing pure niobium plate end-group components according to  claim 2 , wherein a product produced by the method is characterized to be HOM antenna manufactured by said whole press-forming. 
     
     
       4. Aforementioned method of shear-blanking pure niobium plate end-group components according to  claim 1 , wherein shear-blanking speed and motion are controlled by installation of servo mechanism to a press machine including multi-synchronized operation of blank holding force and surface pressure/stress of said material by use of respective multi-action die and servo-die cushion. 
     
     
       5. A method of manufacturing pure niobium plate end-group components according to  claim 4 , wherein a product produced by the method is characterized to be HOM antenna manufactured by said whole press-forming. 
     
     
       6. Aforementioned method of forging pure niobium plate end-group components at said controlling forging temperature according to  claim 1 , wherein formation of surface oxidation film of said near net shape semi-product is temperature-controlled in order to be minimized. 
     
     
       7. A method of manufacturing pure niobium plate end-group components according to  claim 6 , wherein a product produced by the method is characterized to be HOM antenna manufactured by said whole press-forming. 
     
     
       8. Aforementioned method of forging pure niobium plate end-group components at said controlling forging temperature according to  claim 1 , wherein plastic metal-flow of said near net shape semi-product is temperature-controlled to be easily promoted. 
     
     
       9. A method of manufacturing pure niobium plate end-group components according to  claim 8 , wherein a product produced by the method is characterized to be HOM antenna manufactured by said whole press-forming. 
     
     
       10. Aforementioned method of manufacturing pure niobium plate end-group components according to  claim 1 , wherein a grain diameter of said material is several 10 μm to form a proper configuration of fine-grained crystallographic texture. 
     
     
       11. A method of manufacturing pure niobium plate end-group components according to  claim 10 , wherein a product produced by the method is characterized to be HOM antenna manufactured by said whole press-forming. 
     
     
       12. Aforementioned method of forging pure niobium plate end-group components according to  claim 1 , wherein tooling die and punch for said forging are surface-treated followed by being subject to solid-state film type lubricant having dynamic friction behavior independent upon temperature in order to prevent the material from seizure. 
     
     
       13. A method of manufacturing pure niobium plate end-group components according to  claim 12 , wherein a product produced by the method is characterized to be HOM antenna manufactured by said whole press-forming. 
     
     
       14. Aforementioned method of manufacturing pure niobium plate end-group components according to  claim 1 , wherein a press machine is servo-mechanized to control both speed and motion in said shear-blanking and forging. 
     
     
       15. A method of manufacturing pure niobium plate end-group components according to  claim 14 , wherein a product produced by the method is characterized to be HOM antenna manufactured by said whole press-forming. 
     
     
       16. A method of manufacturing pure niobium plate end-group components according to  claim 1 , wherein a product produced by the method is characterized to be HOM antenna manufactured by said whole press-forming. 
     
     
       17. A method of manufacturing pure niobium plate end-group components for superconducting high frequency accelerator cavity used for an acceleration of charged particles, composing of
 (1) shear-blanking procedure of a pure niobium plate different from a conventional fine blanking, wherein tooling punch and die having a very small clearance that is defined as a gap between outer and inner diameters of respective shear-blanking punch and die, cooling-functional device to extract heat generated during successive shear-blanking at high speed on said tooling punch and die, binding tool for preventing movement of said pure niobium plate, multi-action die to control external forces given by press machine tools, servo-die cushion to control blank holding force and surface stress of said pure niobium plate, a press machine installed with servo mechanism for controlling of speed and motion of said pure niobium plate, are all integrated in order to perform shear-blanking of a pure niobium plate material into near net shape semi-products, and 
 (2) forging procedure at different temperature from any of conventional hot, warm, or cold forging, wherein said tooling punch and die along with a heating-cooling device to avoid blue brittleness/necking and to promote plastic metal flow/margin of further press-forming, tooling punch and die aiming at an improvement of formability and minimization of surface oxidation by conducting surface treatment, temperature independent solid-state film type lubricant having temperature independent lubricity to prevent seizure between said near net shape semi-products and forging tools, press machine installed with servo mechanism to control speed and motion of said near net shape semi-products, in order to press-form said near net shape semi-products into final forged products from an original pure niobium plate, are all integrated in order to perform forging of said near net shape semi-products, 
 wherein a manufacturing method of conventional machining or waterjet cutting followed by cold forging of said pure niobium plate end-group components is converted to a whole press-forming method. 
 
     
     
       18. A method of manufacturing pure niobium plate end-group components according to  claim 17 , wherein a product produced by the method is characterized to be HOM antenna manufactured by said whole press-forming.